This was announced ages ago, ad Microsoft finally put out some bits. From Microsoft Downloads:

Windows Easy Transfer Companion enables you to automatically transfer your most important programs from your Windows XP-based PC to your new Windows Vista-based PC. The software will move more than 100 of the most popular programs, as well as many others that you may have installed. You have complete control over selecting which programs to transfer, so only the programs you care about will move. The software will alert you if some programs may not be able to transfer, or may not transfer with high confidence. Most security software is not able to transfer due to technical reasons.

Easy Transfer Companion is designed to be used in addition to Windows Easy Transfer—which is part of Windows Vista and automatically transfers your data and settings. Connecting your two computers can be done with either an Easy Transfer Cable (available online, from retailers, and from PC manufacturers), or a home or small business network. If using an Easy Transfer Cable, you must first install Windows Easy Transfer on your Windows XP-based PC. By using Easy Transfer and Easy Transfer Companion you will be able to quickly and easily setup your new PC with all the data, settings, and programs that matter to you, so you can be productive on your new PC right away.